Recording head actuators are used to move a tape head in a linear direction. Linear actuators are attached to a read/write head by means of a carriage or other supporting structure. A linear actuator, or voice coil actuator, is a DC actuator that produces linear motion in response to a bi-directional analog control signal.
Conventional voice coil actuators have a coil that is actuated to move a read head, a write head or a combined read/write head in response to an analog signal. In conventional voice coil actuators, the coil is disposed around one pole of a stationary magnet.
Voice coil actuators have a coil that has significant mass in comparison to the mass of the head assembly. The mass of the coil is broadly distributed about the actuation axis of the voice coil actuator. Movement of the coil can result in out-of-plane resonant vibrations. Out-of-plane resonance can cause instability, reduce bandwidth and adversely affect performance of the tape head.
The moving coil of a conventional voice coil actuator may be energized by means of a flexible circuit connection, or flex circuit. A flex circuit attached to a voice coil actuator may add mass to the coil that is asymmetrical relative to the actuation axis. Asymmetrical flex circuit connections may also result in out-of-plane resonances. In addition, flex circuits are subject to fatigue failure caused by repeated cycling of the voice coil actuator.
These and other problems are addressed by Applicants' development as summarized below.